The front pages are again dominated by the invasion of Ukraine which escalated when Russian President Vladimir Putin put his nuclear arsenal on “high alert”.

The Guardian and The Independent carry Mr Putin’s nuclear threat and ensuing condemnation from Western leaders, with the latter reporting that the Russian leader is frustrated by the resistance his forces have encountered in Ukraine.

The Daily Telegraph also says the Kremlin has put its nuclear arsenal on standby to try and avoid the “humiliation of defeat” in Ukraine.

The Daily Mail carries the world’s outrage and fury over the threat.

“Vlad’s nukes (are) on standby”, Metro declares, despite plans for peace talks. While The Sun’s front says: “Mad Vlad goes nuclear”.

The Times has Putin saying that his threats are in response to “Nato aggression”.

The Financial Times similarly carries the escalation in tension caused by the Russian president after the UK, US and other nations imposed sanctions on the country’s central bank.

Elsewhere, i and the Daily Mirror focus on the humanitarian aspect to the crisis as 368,000 refugees are forced to flee. Both papers splash with photos of their plight – the latter showing the emotional separation between a little boy and his father who has to stay behind in Ukraine.

And the Daily Star calls Putin “madder than a box of frogs” and features a photo of Kermit the frog calling him a “muppet”.